I'm slightly confused by the mention of "rainbow" patterns. I am imagining multi-coloured, but I doubt that's the desired imagery (unless it's all the minerals they gather).

Please see Addendum XXXX-1 for a list of minerals found encircling SCP-XXXX colonies.

This portion feels like a tonal break, moving away from the 3rd person to directly "speaking" with the reader. Maybe bracket it, such that it is not a direct part of the article.

The number of colonies surrounding a “mature” instance has never been observed above six.

Six what? Are you referring to the colonies, or the ants? You may clarify that aspect.

it is estimated that the time required to reach their “final” depth is ███ years.

This portion implied that SCP-XXXX has not yet reached this "final" depth, but you have already described what happened once they reach the "final" depth.

Pros:

I'm interested in the correlation to the Ring of Fire and their relation to volcanoes. That can be fleshed out however, as it currently feels more like a shout-out rather than properly integrating said concepts.

Cons:

I'm not sure where the article is going. It mentions the ants and a "source colony". They have some relations to volcanoes… Why are the ants collecting those materials? Why do some of these ants build colonies away from their source? How different are SCP-XXXX from SCP-XXXX-1?

The aspect about cultivating species for food… What does it mean exactly? Do they breed them? Hunt them? Or they just appear in the burrows?

Seconding Wrong. Perhaps I'm just stupid, but I have no idea where this SCP is going. The general premise seems solid, so I would suggest expanding the article to explain why they're collecting stuff. Maybe an addendum or two?

- I originally used several different XXXX- numbers to designate different colony types, but I cut it out because I thought it might be too convoluted. I've readded those, so hopefully "ants" (XXXX) "colonies" (XXXX-1) and "source colonies" (XXXX-2) will be a bit more distinct.
- The rings of minerals are just supposed to be what gets excavated, layer by layer, as the ants dig deeper. I've shifted around a lot of stuff, so hopefully that'll get across.
- I only really included the food to indicate that they cultivate and eat things that normal ants wouldn't (cave fish, tardigrades) as they get deeper underground. If it's irrelevant or unnecessary, I can cut it.
- Per psygent and somewhat the volcano connection, I've expanded on what's going on with additional content. (Also, if you're not understanding it, that just means I'm not doing my job :) ) Also, I came up with a title.